N-substituted (5,8-dimethyl-5,6,7,8-tetrahydro-1-naphthyl) carbamates

ABSTRACT

Materials can be protected from attack by insects, mites and nematodes by applying to the material an N-substituted (5,6dimethyl-5,6,7,8-tetrahydro-1-naphthyl)carbamate having the formula   WHEREIN R is a phenyl group or an alkyl radical; X, Y, and Z are substituents independently occupying the 2, 3, and 4 positions; X is hydrogen, fluorine, chlorine, bromine, or lower alkyl; Y is hydrogen, fluorine, chlorine, bromine, nitro, lower alkyl, or lower alkoxy; and Z is hydrogen or nitro. The carbamates, which are novel compounds, are prepared by reacting an isocyanate of the formula RNCO wherein R is as defined above with a 5,8dimethyl-5,6,7,8-tetrahydro-1-naphthol having corresponding X, Y and Z substituents. The tetrahydronaphthol reactants wherein Z is hydrogen can be prepared by cyclialkylating a phenol having corresponding X and Y substituents (Y not being nitro) with 1,5hexadiene in the presence of a catalyst such as aluminum phenate. Tetrahydronaphthols wherein Z and/or Y are nitro can be prepared by nitrating the cyclialkylation product.

United States Patent 1 1 Degginger et al.

1451 Apr. 10, 1973 N-SUBSTITUTED (5,8-DTHYL- 5,6,7,8-TETRAHYDRO-1-NAPHTHYL) CARBAMATES [75] Inventors: Edward R. Degginger, Convent Station; James M. Balquist, Morristown, both of NJ.

[73] Assignee: Allied Chemical Corporation, New

, York,N.Y.

22 Filed: Jan. 8, 1970 21 Appl.No.: 1,567

52 us. (:1. ..260/479 c, 260/471 c, 260/613 D, 260/621 R, 260/622 R, 260/622 P, 260/623 R, 260/624 E, 260/626 T, 424/300 51 1111. c1 ..c076 125/06 [58 Field of Search ..260/491-C, 479 c [56] References Cited UNITED STATES PATENTS 5/1962 Hartle et al ..260/479 4/1963 Lambrech ..260/47l Priniary Examiner-James A. Patten Attorney-Arthur J. Plantamura and Stanley M. Teigland [57] ABSTRACT Materials can be protected from attack by insects, mites and nematodes by applying to the material an N- substituted (5 ,6-dimethyl-5 ,6,7 ,8-tetrahydrol naphthyl)carbamate having the formula RNHCO? CH:

X, Y, Z

, phenol having corresponding X and Y substituents (Y not being nitro) with 1,5-hexadiene in the presence of a catalyst such as aluminum phenate. Tetrahydronaphthols wherein Z and/or Y are nitro can be prepared by nitrating the cyclialkylation product.

6 Claims, No Drawings N-SUBSTITUTED (5,8-DlMETHYL-5,6,7,8- TETRAHYDRO- l -N APHTHYL) CARBAMATES t the material an effective amount of an N-substituted (5,8-dimethyl-5,6,7,8-tetrahydro-l-naphthyl)carbamate having the formula RNHCO O CH;

wherein R is an alkyl radical of l to carbon atoms,

. phenyl orlower alkyl substituted phenyl; X, Y and Z are substituents independently occupying the 2,3, and 4 positions; X is hydrogen, fluorine, chlorine, bromine, or lower alkyl; Y is hydrogen, fluorine, chlorine, nitro, bromine, lower alkyl, or lower alkoxy; and Z is hydrogen or nitro, preferably hydrogen. The terms lower alkoxy and lower alkyl refer to such groups having from 1 to 4 carbon atoms.

The carbamate is-applied to the material to be protected in the form of a pesticidal composition comprising the carbamate and a suitable diluent which forms a fine dispersion of the carbamate on plants or'other materials to be protected. Suitable solid diluents include talcums, diatomaceous earth, wood flours, and silica gels. Where the diluent is a solid, the composition preferably contains from 0.1 to 1.0 weight percent of the carbamate. Suitable liquid diluents include water, acetone, petroleum distillates and the like. Where the diluent is a liquid, the composition can contain as little as about 0.5 pound of carbamate per 100 gallons of diluent, the preferred concentration being from 0.5 to 2 pounds of carbamate per 100 gallons of diluent. Other pesticidal adjuvants, including conventional wetting, dispersing, and emulsifying agents, can also be added to the formulation. The amount of carbamate deposited on the material can range from 0.01 to 1.0, preferably 0.1 to 0.5 pounds of carbamate per square yard of material. Nophytotoxicity is'shown by any of the carbamates.

The carbamates of this invention can be prepared by reacting a 5,B-dimethyl-S,6,7,8-tetrahydro-l-naphthol having corresponding X, Y, and Z substituents with an isocyanate of the formula RNCO wherein R is an alkyl or phenyl radical as defined above. The alkyl and phenyl radicals may contain substituents, such as halogen atoms, which do not adversely affect the pesticidal effectiveness of the carbamates. The alkyl radical can include a cycloaliphatic ring and can also contain other atoms, such as oxygen forming an ether linkage, in the alkyl chain. R is preferably phenyl or an alkyl radical of l to 6 carbon atoms. The reaction is preferably carried out in the presence of an excess of the isocyanate, which also serves as a solvent for the naphthol. In addition, it'is. desirable, but not absolutely necessary, to adda small amount of an organic base such as triethylamine to the reaction mixture in order to catalyze carbamate formation. The reaction, which is exothermic, proceeds readily without the external addition of heat. When the reaction mixture is heated to reflux fora brief period, such as about thirty minutes, a nearly quantitative yield of carbamate is obtained. The carbamates can be recovered fromthe reaction mixture by removing unreacted isocyanate under reduced pressure, followed by recrystallization of the residue.

The tetrahydronaphtliols from which the carbamates of this invention are derived can be prepared by reacting, in the presence of a suitable catalyst, 1,5-hexadiene with a phenol having the formula:

wherein X and Y independently occupy the 2, 3 or 4 positions; X is hydrogen, fluorine, chlorine, bromine, or lower alkyl; and Y is hydrogen, fluorine, chlorine,

' bromine, lower alkyl or lower alkoxy. The reaction product is a 5,8-dimethyl-5,6,7,S-tetrahydro-1- naphthol having substituents in the 2, 3, and 4 positions corresponding to the substituents in the 2, 3, and 4 positions of the substituted phenol reactant. If Y is lower alkoxy, X is preferably hydrogen; if Y is halogen, X is preferably hydrogen or a like halogen; and if Y is lower alkyl, X is preferably hydrogen or lower alkyl. Carbamates wherein vX and Y are both hydrogen are also preferred.

Suitable catalysts for preparing the tetrahydronaphtholreactant include boron trifluoride etherate and aluminum phenate (triphenoxyaluminum), with aluminum phenate being preferred. The aluminum phenate'catalyst can be prepared in situ by heating a suspension of aluminum and the substituted phenol to be employed in the cyclialkylation reaction to between about C and 200C until hydrogen evolution has ceased. Alternatively, the aluminum phenate catalyst can be prepared beforehand from the same or different phenolic reactant and stored prior to use. Hence, as used herein, the term aluminum phenate" includes aluminum phen'ates derived from unsubstituted phenol and substituted phenols having the formula:

wherein X and Y are as defined herein.

The weight ratio of catalyst to 1,5-hexadiene can be from about 1:100 to about 110.5, with the preferred ratio being from about M0 to about 1:1.

The reactants can be added to the reaction mixture in any desired ratio, but normally it is desirable to employ an excess of the substituted phenol to avoid undesirable side reactions producing higher molecular weight by-products. If desired, an inert solvent can also be added to the reaction mixture. Suitable solvents in .clude chlorobenzene and nitrobenzene. Lower boiling solvents, such as carbon disulfide, can also be used at tions unsubstituted. It is desirable, but not essential, to

carry out the reaction with the tetrahydronaphthol reactant dissolved in an inert solvent, such as dioxane. The reaction proceeds readily at ambient temperatures. Both monoand dihalogenated products (separable by fractional distillationlcan be prepared by this method.

The tetrahydronaphthols of this invention wherein Z and/or Y are nitro are prepared by treating with nitric acid a 5,8-dimethy1-5 ,6,7,8-tetrahydro-l-naphthol having either or both of the 2 and 4 positions unsubstituted. Theconcentration of the nitric acid is not about 90 percent, with the range 70 to 90 percent being preferred. The reaction proceeds readily at ambient temperature, but temperatures ranging from "C to 100C can be used if desired. It is desirable, but not essential, to carry out the reaction with the tetrahydronaphthol reactant dissolved inan inert solvent, such as ether. Both monoand dinitro products .(separable by chromatography) can be prepared by this method.

The following examples further illustrate the invention. In each of the examples the reaction products were identified by infrared spectrum and nuclear magnetic resonance analyses.

EXAMPLES 1-7 held at the indicated temperature for the indicatedperiod of time after the addition was completed. The reaction mixture was then cooled, poured onto a system of ice and hydrochloric acid, extracted with ether and then dried over sodium sulfate. The desired 5,8-dimethyl-5,6,7,8-tetrahydro-1-naphthol was then lated below in Table 1.

isolated by distillation. The results obtained are vtabuadded to a rapidly stirred solution of 8.7 grams of 5,8- dimethyl-S,6,7,8-tetrahydro-l-naphthol in 100 ml of dioxane until a yellow color persisted (about ml required). The dioxane solution was poured into 200 give 15.5 grams of 2,4-dibromo-5,8-dimethyl-5,6,7,8-

tetrahydro-l-naphthol, boiling point 137-139C at 0.9 mm Hg.

EXAMPLE9 tetrahydro-l-naphthol in 200 ml of ether was treated with 50 ml of percent nitric acid with external cooling. The ether solution was then extracted several times 20 with water, dried over sodium sulfate and concentrated especially critical and can range from about 10 to to dryness under vacuum. The residue was chromatographed using a 50 X 4.5 cm column of silica gel and eluted with a 1:1 solution of hexane and chloroform. The first 1300 ml of eluent were concentrated to dry- 25 ness and the residue was crystallized from hexane to give 7.6 grams of yellow crystals, melting point 7288 C. These crystals were rechromatographed with hex-.

3O nitro-5,6,7,8-tetrahydro-l-naphthol. Further elution with a 4:1 soltuion of hexane and chloroform afforded 5.0 grams of yellow-green crystals, melting point 9294C, identified as 5,8-dimethyl-2,4-dinitro- 5,6,7,8-tetrahydrol-naphthol.

EXAMPLE l0 One-half ml of triethylamine was added to a stirred solution of 3.8 grams of 5,8-dimethyl-5,6,7,8-

40 tetrahydro-l -naphthol and 10 m1 of methyl isocyanate.

45 chloroform-hexane to give 2.1 grams of product. Concentration of the mother liquor afforded an additional 1.0 grams of product. Two recrystallizations of the product from hexane gave white crystals, melting point 100.5l02C, identified as N-methyl (5,8-dimethyl- 5,6,7,8-tetrahydro-1-naphthyl)carbamate.

The carbamate prepared above was diluted with a 1:1 solution of acetone and water to a concentration TABLE 1 Grams 5,6, 7, 8- Renctetra- Urams Grams tion hydro-1- Grams alumi- 1, fi- Reaction time, n iphthol Boiling point, Phenol phenol num hexadienc Lenin, C. hours (yield) (.lmm. Hg

Unsubstituted. 150 3 34.11 180-185 3. 5 -11 118-1011/1. 0 2-methyl 208 3 51. 7 160-170 -1 78 .Il-1l3/0. 5 3-methyl 200 l 51. 7 170-180 1 31) 1'30-130/0, 12-0. 3 4-methyl 220 l 61. 7 160-185 5 58 1;!1-103/0. Z5 4-othy1 200 l 51. 7 -215 11 -12 -114/0. R 2-isopr0pyl 3 3-1. 6 200-215 .2 50 110-113/0. 3 4-methoxy 200 4 51. 7 215-230 .3 51 135-145/(15 EXAMPLE 8 A solution of 45 grams of potassium bromide, 30 grams of bromine, and 300 m1 of water was slowly corresponding to one pound of carbamate per 100 gallons of diluent. The solution was sprayed on cranberry bean plants which were subsequently infested with A solution of 10 grams of 5,8 -dimethyl-5,6,7,8-

Mexican bean beetle larvae after the solution had dried on the plants. The solution was also sprayed on English broad beans and pea aphid adults, separately, and then the aphids were placed on the treated plants. In addition, the solution was sprayed on cranberry bean plants infested with two-spotted spider mites. A portion of the solution was stripped of acetone, diluted with water to a concentration of 500 ppm of carbamate, combined with 0.1 percent by weight of Triton X-l55 wetting agent, and sprayed on sour mash nematodes (Panagrellus redivivus). Mortality observations were made three days after treatment. The percent of nematodes killed was determined by visual estimate using a microscope. The results are reported in Table II.

EXAMPLES 11-23 Other N-substituted carbamates were prepared following the general procedure of Example 10 from certain other naphthols. These carbamates were similarly tested for pesticidal effectiveness following the procedure of Example 10, with the exception that the concentration of the carbamate was equivalent to two pounds of carbamate per 100 gallon of diluent. The results are reported below in Table 11.

TABLE II Carbamate Percent Killed R X Y Z MBBL PAA' TSSM NEM CH, H H H 100 80 7 35 CH, 4-methyl H H 100 5.9 20 CH, 4-chloro H H 100 0 18.7 10 CH, Z-methyl H H 20 0 14.3 100 CH, 4-ethyl H H 40 100 4.2 10 CH, 2-isopropyl H H 0 10 17.6 CH, 4-methoxy H H 40 0 13.3 CH, 3-methyl H H 100 100 57.1 10 C,H, H H H 20 0 33.3 10 c-C,H H H H 60 0 15.4 5 CH,(CH,), H H H 40 0 53.9 10 CH,(CH,), H H H 60 0 100 10 CH, 2-bromo 4-bromo H 100 0 O 10 Mexican bean beetle larvae Pea aphid adults Two-spotted spider mites Sour mash nematodes We claim:

1. An N-substituted 5 ,8-dimethyl-5 ,6,7,8-tetrahydrol-napthyl carbamate having the formula VRNHCOO an. 7

wherein R is an alkyl radical of l to 6 carbon atoms or phenyl; X is hydrogen, Y is a lower alkoxy and Z is hydrogen.

2. An N-substituted 5,8-dimethyl-5,6,7,S-tetrahydrol-napthyl carbamate having the formula 12.31am 0m wherein R is an alkyl radical of l to 6 carbon atoms or phenyl; X is hydrogen, Y is fluorine, chlorine or bromine and Z is hydrogen.

3. An N-substituted 5,8-dimethyl-5,6,7,8-tetrahydrol-napthyl carbamate having the formula R NHC o 0 0 Ha wherein R is an alkyl radical of l to 6 carbon atoms or phenyl; X and Y are lower alkyl and Z is hydrogen.

4. An N-substituted 5,8-dimethyl-5,6,7,8,- tetrahydrol -napthyl carbamate having the formula X, Y,Z 

2. An N-substituted 5,8-dimethyl-5,6,7,8-tetrahydro-1-napthyl carbamate having the formula
 3. An N-substituted 5,8-dimethyl-5,6,7,8-tetrahydro-1-napthyl carbamate having the formula
 4. An N-substituted 5,8-dimethyl-5,6,7,8,-tetrahydro-1-napthyl carbamate having the formula
 5. The carbamate of claim 4 wherein R is an alkyl radical of 1 to 6 carbon atoms.
 6. The carbamate of claim 5 wherein R is methyl and X is methyl occupying the 3 position. 